Excavator tooth



April 15, 1941. w. E. SOBERANES EXCAVATOR TOOTH Filed Aug. 5, 1939 2 Sheets-Sheet l INVENTOR$ M 5 .faazsAA/Es A ril 15 1941. w. E. SOBERANES 2,238,081

EXCAVATOR TOOTH Filed Aug. 5, 1939 Sheets-Sheet 2 INVENTORS M15 505AN5 z w a ATTORNEYS Patented Apr. 15, 1941 season OFFICE EXCAVAT'OR TOOTH Waverly Edward Soberanes,

San Rafael, Callf.,

assignor of one-half to Abraham W. Ward, San

Francisco, Calif.

Application August 5, 1939, Serial No. 288,534

7Claims.

This invention relates to excavation teeth such as are used on steam shovels, trench machines, and other types of excavators, earth or rock moving apparatus. Teeth of this character are subject to extreme conditions of wear, and it is desirable to provide the teeth with removable and renewable points so that when the digging point breaks or wears out it may be removed and replaced without the necessity of discarding the base portion of the tooth.

It is an important object of my invention to provide a tooth having a removable point construction in which the point is very firmly mounted on the base of the tooth, so that it cannot be dislodged during the digging. At the same time it is important that the point be easy to apply and easy to remove so that valuable time will not be lost in changing a point when necessary. These results are accomplished by my invention.

It is another important object of my invention to provide a tooth point construction in which the actual digging tip of the point is so formed as to maintain a sharp condition suitable for efiective digging throughout a long period of use. is accomplished by providing the digging point oi the tooth with a reinforcing rib which reiniorces the tip against breakage and at the same time results in causing the tooth to wear In a preferred form of my invention this into a pointed shape so that it does not lose an eflfective digging edge or point throughout the very considerable period of use. The effective iife or the point is thus greatly extended. The formation of the tip of the tooth is such that the point may properly be characterized as selfsharpening."

Other objects and advantages of the invention will appear in the course of the following description of certain forms or the invention chosen to illustrate the principles thereof, and the best modes now known to me for practicing the same. In the accompanying drawings forming part of the specification:

Figure. 1 is a diagrammatic fragmentary side elevation of a part 01' an excavator dipper showing one application of the tooth of the present invention;

Figure 2 is a perspective view of one form of tooth base;

Figure 3 is a perspective view or one form of tooth point adapted to be applied to the base shown in Fig. 2;

Figure 4 is a section through the tip of the tooth taken on line 4-4 of Fig. 3, the dotted lines showing the approximate shape of the section after wear: I

Figure 5 is a back or outside view of the complete tooth;

Figure 6 is a longitudinal section of the tooth taken on line 6-8 of Fig. 5;

Figure 7 is a transverse section through part of the assembled tooth taken on line 1-1 of Fig. 6, and showing the securing lugs on the point in engagement with the tooth base;

Figure 8 is a perspective view of a modified form of tooth;

Figure 9 is a perspective view of a modified form of tooth base adapted to receive the form of point shown in F1 8;

Figure-'10 is a gerspectlve view of"another modified form of point;

Figure 11 is a perspective view of the corresponding base for receiving the same;

Figure 12 is a perspective view of another modiiied form of point;

Figure 13 is a view in longitudinal section showing the point of Fig. 12 attached to a base formed to receive the same.

Figure 14 is a framgentary perspective view of the tooth base shown in Fig. 13;

Figure 15 is a fragmentary view in longitudinal section showing a modified form of base and a removable point, the point being provided with a shield portion for protecting the base from wear;

Figure 16 is a view in longitudinal section of another form of tooth base and point, showing a modified means for attaching the point to the ase;

Figure 17 is a back view shown in Fig. 16;

Figure 18 is a perspective view of another modified form of assembled tooth; and

Figure 19 is a cross section on line 20-40 of Fig. 18 of the assembled tooth.

Referring to the drawings in detail, the improved excavator tooth comprises a base or body 20 and a removable point 2|. The base 20 may be made to form part of, or be secured to the of the base and point excavator element in any suitable manner. For

trans erse seat 32 on its front face and with a raised projection 33 on its back, at each side of which is formed a recess 34 to receive one of the attaching lugs on the point to be described. The slot 3| extends into the tooth body beyond the shoulder 32 and terminates in an end wall 36. A wall portion 31 overlying the rear end of the slot 3| (Fig. 6) is thus provided for-a purpose which will be explained.

The tooth point comprises a face member 40 which is preferably formed of very hard and tough metal such, for instance, as an alloy steel adapted to withstand wear and shock. This face 40 is extended at its forward end into a sharp tip or digging edge 4| which may be of any suitable formation adapted to conditions of use. The inner end 42 of the face 40 is adapted to abut against the shoulder 32 on the base. The tooth point is also provided with a web 44 which is adapted to be received in the slot 3| with its inner edge 45 seating against the bottom 36 of the slot. The corner 41 of the web overlies and engages the wall 31 at the bottom of the slot so as to reinforce and support the tooth point against possible displacement when digging under severeconditions. The back of the tooth point is provided with flange portions 50 projecting laterally from the sides of the web 44 and adapted to overlie the inclined faces of the lugs 30. The rear ends of the flange portions 50 are formed to provide bendable ears 5| which may be of any suitable shape. For instance, the flanges may be notched out slightly at each side of the web, as shown at 52 in Figure 3 so as to provide ears of somewhat pointed shape. When the point is applied to the base of the tooth, as shown in Figs. 5, 6 and 7, the ears 5| are bent over into the recesses 34 and hammered down firmly against the rear ends or shoulders 35 of the lugs 30, thereby firmly retaining the tooth point upon the base. when it is desired to remove the tooth point, it is merely necessary to bend up these lugs, which may be accomplished by means of any suitable tool, such for instance as a cold chisel. The recess 34 and the ears 5| are so shaped and positioned that the ears are easily accessible to the blows of a hammer for applying the point, or to a chisel or other tool for removing the point. The securing means consisting of the bendable lugs is very effective as it is very easy to hammer them over into tight engagement with the surface 35, so as to hold the tooth point in place. They are well protected from wear by the formation of the base of the tooth, and the projecting portion 33 of the tooth base extends slightly above the level of the outside of the flanges 50 so that they and the ears 5| are protected from heavy wear by this formation.

The support of the tooth point on the base is extremely firm as the endwise thrust on the tooth point is taken up by direct engagement of the end 42 of the working face 40 and shoulder 32 on the tooth base and also by the engagement of the end of the web against the end wall of the slot 36. Rocking movement of the tooth point about the base is resisted by the tight fit of the lugs 30 between the flanges 50 and face 40 and by engagement of the corner 41 on the web behind the shoulder 31 on the base, aswell as by the engagement of the web and face of the tooth against the surfaces 36 and 32. As the bendable ears 5| hold the parts in tight assembled relationship the construction is as solid as if integral and at the same time the advantages of a removable point are secured, including the advantage of being able to use a point having a very hard and wear resistant working face and tip.

In the preferred form of my invention the removable tooth point is provided with a reinforcing rib 60 on its back which extends approximately to the working edge of the tooth and rearwardly over the web 44 and flange portions II preferably to near the rear end of the removable tooth point. The rib 60 is thus of substantially triangular shape in side elevation, thus acting to brace the cutting tip 4| against danger of breaking off under heavy shocks. The rib 60, which may be made of hard, wear resistant metal, similar to that of the face 40, also acts to resist wear so that as the point or cutting edge of the tooth wears down it will wear away most slowly adjacent to the rib 65. Thetooth will thus tend to become more or less sharply pointed so that its ability to penetrate and dig the dirt is not lost. As shown in Fig. 4 it; will be seen that the cross section of the point of the tooth is of T-shape and as it wears away this T-shape will persist as indicated by the dotted lines in Fig. 4, and an effective digging point will be maintained. The use of rib 50, while desirabie, is not in allcases necessary, and in some instances the rib may be omitted, as in the form of tooth shown in Fig. 8.

Figures 8 and 9 show a modified construction for securing the tooth point to the base. In this instance the flange portions a are slotted at 15 so as to provide bendable tongues I8 which are adapted to be bent downward into notches H in the lugs 30a of the tooth base.

Figures 10 and 11 show another modification in whichthe flange portions 501) are provided.

with bendable tongues 33, adapted to be bent downward laterally into recess 8| formed in the upper part of the lugs 30!) of the tooth base.

Figures l2, l3 and 14 show a means for at- I taching the tooth point to the base without the use of bendable lugs. In this construction the web a is provided with an extension terminating in a threaded stem 86. The stem 86 passes through a slot 88 in the tooth base and a nut 89 is screwed on the stem for drawing the tooth point tightly against its seat in the base and retaining it firmly in position. A cross pin |2Fi passing through holes ME in the tooth base and a hole i2? in a part of the web may be provided for retaining the point on the tooth base, where desired. A screw and nut connection of this kind is suitable under certain conditions, but for severe use it is usually found to be not as satisfactory as a form using bendable ears or lugs in which there are no threads to strip or rust. The bendable ear construction can always be removed by the use of a hammer and chisel so that there is no danger of delay in trying to remove a rustedconnection. The bendable ear construction is also very cheap to manufacture.

Figure 15 illustrates a construction in which the tooth point face 600 is extended so as to cover the front of the tooth base. For this purpose the tooth point face is shown as provided with an extension flange 90 of the same hard, wear resisting metal as the face and which overlies and protects the front of the tooth base.

Figures 16 and 17 show another modified construction of means for securing the tooth point to the base. In accordance with this construc tion the rear ends of the flanges 50d are spring tempered so as to provide spring arms 92 which are formed with transverse ribs or projections 93 at their inner ends which are adapted to snap into recesses 94 in the tooth base. With this construction the tooth point may be merely snapped into position without permanently bending over ears or tongues. This construction, like the bolt construction, is best adapted for use under less severe conditions, as the malleable bendable lugs or tongues now appear to be the most satisfactory for hard service.

Figures 18 and 19 show a modified construction of tooth in which the tooth point-instead of being provided with a web fitting in a slot in the base, is formed with ribs engaging grooves in the base. For instance, the flange H at the back of the tooth may be provided with a single rib Ill seated in a groove H2 at the back of the tooth base, while the tooth face H5 is provided on its inner surface with a. pair of ribs H6 seating in grooves H1 in the tooth base. The engagement of these ribs and grooves serves to hold the tooth point against lateral displacement on the tooth base. However, the web construction previously described is preferred, as the web forms an effective means for bracing the flanges and face of the tooth point together and preventing bending or spreading of one part relative to the other. 7

While I have illustrated anddescribed in detail certain preferred forms of my invention,

it is to be understood thatchanges may be made -therein and the invention embodiedin other structures.

myself to the specific constructions. illustrated, but. intend to cover inventiombroadlyin I do not, therefore, desire tolimit whatever form its principle may be utilized.

-1. A digging tooth comprising a base having a wedge shaped body and a tooth point removably secured thereon, said tooth point including a face member of wear resistant metal and a-flange member attached at its forward end to the face member and diverging rearwardly therefrom, said face and flange members fltting against opposite inclined side faces of the tapered tooth body, the inclined face of said tapered tooth body engaged by said flange member being formed with looking recesses located at each-side of the center thereof, said recesses opening outwardly at the sides of said tooth body so as to permit a hammer to be swung thereinto, the forward walls of said recesses nearest to the point of the tooth forming retaining shoulders, and said flange member being formed with bendable ears bent into engagement with the forward walls of said recesses.

2. A digging tooth comprising a base, tapered supporting lugs thereon separated by a slot the back of said lugs being formed to provide shoulders facing away from the outer end of the tooth, and a. removable tooth point mounted on said base and comprising a face member supported by said tapered lugs and having a web projecting from the rearthereof through the slot between said lugs. and flange members attached to said web and engaging the backs of said lugs, said flange members being provided with bendable ears,bendable into en gement with the shoulder portions of said lugs on said base to interlock therewith and retain said removable point on said base.

in said slot and extending beyond said transverseshoulder on said base so as to lie behind and be supported by said shoulder forming portion, said tooth point also having flanged portions diverging from said face member and attached to said web, said flanged portions engaging the other inclined faces of said tapered lugs, said flange members being provided with bendable portions adapted to be bent into interlocking engagement with portions of said base member.

4. A digging tooth comprising a basehaving a tapered body, and a removable tooth point mounted on said body, said removable point including a portion fitting against one side of said tapered body and comprising a substantially flat digging faceof wear resistant metal extending into a prolonged tip or digging edge, a back member secured to said digging face portion and fitting against the back of said tapered body, and a central reinforcing rib for said tip extending longitudinally from near the center of the digging edge of said tip to said back member, said digging face portion of the digging point and said rib constituting a digging tip of substantially T- shape cross section whereby, as wear takes place, said tip will tend to continuously wear into a pointed shape suitable for eflective digging.

5. A removable point for a digging tooth comprising a face member of wear resistant metal extending into a digging edge, a flange member of malleable metal secured at its forward end to and diverging rearwardly from said face member, and a longitudinally extending central web connecting said face and flange members, said malleable flange member being formed to provide said plane for securing said removable point to a tooth body.

6. A base for a digging tooth having support-- ing lugs thereon separated by a longitudinal slot, said lugs terminating at their ends remote from the point of the tooth in transverse shoulders, said base having a raised portion at the rear of said slot between said shoulders formed to pro.-

vide open. sided locking recessesof which said shoulders form theforward walls.-

7. A base for a digging tooth having support-' ing lugs thereon separated by a slot, said lugs terminating at their ends remote from the point of the tooth in transverse shoulders, said base having 'a raised portion at the rear-of said slot between said shoulders formed to provide locking recesses of which said shoulders form the forward walls, and said base also having a, portion at the opposite side thereof from said recesses forming a. transverse shoulder facing, the point. of the tooth, said shoulder forming portion overlying and closing a portion of the slot adjacent thereto.

wAvEanY EDWARD soBEnANEs. 

